Aircraft instrument



MPU, Y; 9@ L. DE FLowEz AIRCRAFT INSTRUMENT Filed April 18, 1945 5She'ets-Sheet l Jg., JNVENTOR.

` LUIS DE FLOREZ,

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"35W WU L. DE FLQREZ AIRCRAFT INSTRUMENT Filed April 18 1945 5Sheets-Sheet 2 INVENTOR. Luls DE FLQREZ ATTORNEY,

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` INVENTOR. LUIS DE FLOREZ ATTORNEY.

L. DE FLOREZ ,496'M AIRCRAFT INSTRUMENT Filed April 18, 19545 5Sheets-Sheet 5 I N VEN TOR. ))\}\A`z. LUIS DE FLOREZ WL M Patented Feb.7, 1950 AIRCRAFT INSTRUMENT Luis de Fiorez, United States NavyApplication April 18, 1945, Serial No. 589,004

(Cl.` :i3-204) (Granted under the act of March 3, 1883, as`

amended April 30, 1928; 370 O. G. 757) 6 Claims.

The present invention relates to aircraft instruments. It is the generalaim of the invention to simplify instrument night and provide for easierand safer flight under instrument conditions.

This aim is accomplished by the provision of a novel and improved threedimensional flight instrument, in which a single indicator gives thepilot complete information as to bank, dive and climb, and turn. Thatis, the instrument not only shows the angles of dive, climb and bank,but also shows the direction and rate of turning movements.

In this respect, it affords a true simulation of the actual horizon,since the real horizon, unlike conventional horizon instruments, gives atrue three-dimensional reference.

It is well known that when the pilot can see the actual horizon itrequires no more than a glance for him to determine his attitude in allthree planes of space. That is, the angle between the horizon and thewing tips of the plane indicates the direction and the amount of bank,while the angle between the horizon and the flight path of the planeshows whether the plane is climbing, diving, or flying level. Moreover,the actual horizon gives an indication of therate and direction of anyturning movement of the aircraft, since the horizon invariably includeslandmarks such as buildings, lights, or plumes of smoke, and any turningmovement of the aircraft will result in an apparent sidewise motion ofall these landmarks along the horizon. As an example, assuming that aplane is flying a level course and maintaining the wing tips level. Thehorizon will appear stationary if the course of the plane is exactlystraight. However, if the plane is turning to the right, for example,any landmarks on the horizon will appear to be drifting from right toleft across the horizon. The rate of speed of their apparent movementwill be dependent cn the rate of turn of the airplane.

This phenomenon is so well known to pilots that they respond to it andcorrect the course of the plane without conscious effort. It isunnecessary for them to engage in a conscious mental evaluation of theoptical picture of the horizon and to determine the direction and rateof turn consciously. Rather, they instinctively know the amount of turnand correct for it automatically.

From the foregoing, it will be seen that although the pilot of a planein contact flight can determine his attitude in three dimensions byreference to the actual horizon, the aircraft instruments heretoforeknown and commonly used have been unable to accomplish the same effect.The standard type of gym-horizon commonly used is capable of giving anindication of bank and 0f climb, but gives no indication of rate ofdirection of turn. Thus, it falls short of a true simulation of theactual horizon, and requires the pilot to divert his attention fromobservation of the horizon to a directional gyro or turn indicator, andthen to mentally evaluate the combined readings of several instrumentsto determine the position of the aircraft.

One of the principal objects of the'present invention is to provide aflight instrument including a synthetic horizon indication designed togive a more natural and realistic simulation of the actual horizon thaninstruments heretofore known, so that the instinctivereaction of a pilotto the appearance of the actual horizon will carry over and allow him tofly under instrument conditions with the same degree of naturalness aswhen the actual horizon is visible and available as a reference.

A further object of the invention resides in the f provision of a threedimensional flight instrument including a horizon indicator and meansfor maintaining it in level horizontal position, together with means forcausing landmark indications to move sidewise across the horizon inresponse to turning movements of the aircraft.

Referring now more particularly to the drawings attached to and forminga part of the present specification.

Figure l is a front elevational view of a simulated horizon ascontemplated by this disclosure.

Figure 2 is a side elevational view of the instrument illustrated inFigure 1 with certain parts of the housing broken away to show theoperating mechanism.

Figure 3 is a fragmental` detail sectional View taken substantially onthe plane of the line 3-3 in Figure 2.

Figure 4 is a detail sectional view taken substantially on the plane ofthe line 4 4 of Figure 2.

Figure 5 is a reduced scale face View of the instrument as it appearswhen the aircraft is in a banking turn to the right.

Figure 6 is a reduced scale face View of the instrument as it appearswhen the planeis exeouting a banking turn to the left.

Figure 'I is a detail sectional view taken sub stantially on the planeof the line 1-1 of Figure 1. i

Figure 8 is a fragmental side elevational View,

3 partly in section, showing a modied form of the invention, and

Figure 9 is a fragmental detail sectional view taken substantially onthe plane of the line 9--9 of Figure 8.

The instrument illustrated includes, in general, a gyro-horizon orattitude gyro, and a directional gyro mounted in close association witheach other on the instrument panel I0. The attitude gyro is housed in acase II and includes a dial I3 and a horizon indicating bar I4 connectedto a rotating gyroscope I by a mechanical linkage I6. Thus after theinstrument is originally set and the cage knob I 'I is turned to releasethe gyroscope mechanism, the operation of the gyroscope I5 will serve tomaintain the horizon indicating bar I4 in horizontal positionirrespective of normal banking, turning, or diving movements of theairplane.

The directional gyro is ho-used in a. case I2 and includes a dial 2I anda compass card 22 positioned adjacent to the dial and controlled in itsmovement by a rotary gyroscope mechanism 23. The directional gyro alsoincludes a caging knob 24 so that when the compass card has beenproperly set and the caging knob released, the directional gyroscope 23will function to maintain the compass card' 22 stationary, despitenormal turns and maneuvers of the airplane. The directional gyro isutilized in combination with the gyro-horizon in a manner to be laterdescribed, but it may also be provided with a dial window so that thepilot may view the compass card in the conventional manner.

Since the operating mechanisms of conventional attitude gyros anddirectional gyros are well known in the iield of aviation instruments,and since the mechanical details of these instruments form no part ofthe present invention except in combination with the features dei-inedin the claims, the structural details of these instruments will not bemore fully described in this disclosure.

It has been previously stated that one of the objects of the inventionis to provide a horizon indicator wherein landmark indications arecaused to move sidewise along the horizon in response to turningmovements of the aircraft. These landmark indications may be moved alongthe horizon mechanically if desired, but to avoid mechanical frictioninsofar as possible, the present'disclos'ure contemplates causingoptical landmark indications to move along the horizon. This is done byprovidingan illuminated eld associated with the directional gyro I2, sothat whenever'the plane turns to right or left, the illuminated eld willshift in the opposite direction and cause apparent longitudinal motionof the landmark indications along the horizon bar I4. Thus, a turn tothe right results in an apparent drift of all horizon landmarks fromright to left, while a turn to the left results in an apparent 'drift ofthe landmarks from left to right. Obviously, the landmarks may be causedto shift in either direction but the direction of movement indicatedgives an accurate simulation of the apparent sidewise movement of reallandmarks as observed along the actual horizon in front of a plane Whena turn is being executed.

To this end, a light source such as the incandescent lamp l25 is mountedin a removable plug socket 26 positioned in the panel II! between theattitude gyro dial I3 and the directional gyro dial 2l. Electricalconnections to the incandescent lamp 'are established through a'pair ofleads 21 and 28, which establish contact with separable connectors 29and 3l in the plug socket 26. The incandescent lamp 25 is carried by atubular socket extension 32 so that it will extend into an opticalscreen formed in the shape of a small rotary drum 33 having slots 34 inits outer surface to `provide a series of alternate opaque andtransparent portions. The drum 33 is rotatably mounted on a shaft 35 andis driven by a bevel gear B which meshes with a matching bevel gear 3'!secured to the vertical spindle of the directional gyroscope 23. Thearrangement is such that when the airplane makes a turn to the right orleft, the relative movement of the casing I2 of the directional gyroaround the compass card 22 and gyroscope 23, which maintains a fixedposition in space, will cause the bevel gear 36 to rotate and move theindividual slots 34 of the drum in a progression across the window 38 inthe cover box 39 surrounding the drum.

The light from the incandescent lamp 25 passes through the individualslots 3d of the drum 33 to form a plurality of divergent light beamswhich pass upwardly through the Window 38 to a conrdensing lens lilmounted in the housing of the attitude gyro i5. The lens 4! refractsthese light rays somewhat as indicated in Figure 3, so as to form anilluminated field consisting of a multiplicity of generally parallelrays, and to project the ield upwardly toward the horizon bar I4. Asillustrated, the horizon bar I4 is square in crosssection and is set atan angle to provide an angular reflecting surface to pick up light raysfrom the illuminated iield and reflect them out through the dial Windowof the instrument. If desired. the horizon bar d may be provided withany type of high reiiection coating. In any event, the individual lightbeams of the illuminated field will form light and dark areas 42 on thehorizon bar I4. These areas may be referred to as landmark indications,.since they move in a sidewise direction across the horizon when theaircraft is in a turn and thus 'substantially duplicate the apparentmovement oi landmarks on the actual horizon.

It sho-uid be particularly noted that the apparent direction of movementof these landmark indications is directly along the line of the horizon,irrespective whether the airplane is iiying level as illustrated inFigure 1 or Whether it is banking to the right or left as indicated inFigures 5 and 6 respectively.

It will be apparent that the angle of bank will be indicated by theangle existing between the xtures of the aircraft and horizon indicatingbar while any turn to right or left will be indicated by movement of thelandmark indications along the bar I4. The angle of dive or climb of theaircraft is also indicated by the relative position of the horizon barwith respect to the dial and accurate observation of the angle of diveor climb is facilitated by the provision oi a reference marking which isshown in the structure illustrated as comprising a semicircular yoke 45having a pair of oppositely disposed tabs 46 extending into the field ofvision of the dial I3, so that the position of the tabs 4B may becompared with the gyroscopically controlled horizon bar to give avisuall indication of the angle of dive or climb. However, in View ofthe fact that the apparent angle of climb or dive isvdependent on theangleof attack of theaircraft as well as on its course of iiight,meansare provided for raising or lowering the tabs 46 to trim theinstrument to give altrue' reading. For this purpose, the yoke 45 ismounted on a vertical guide il so that it may be moved upwardly ordownwardly by the gear pinions 48, "59, and 56, arranged to transmitmotion from the trim knob 52 to the rack 53 carried on the slide of theyoke 5.

The form of the invention illustrated in Figures 8 and 9 is identicalwith the form just described, except that the housing of the attitudegyro 55 is formed to include a hollow bracket 56, which interconnectsthe housing 55 with the housing of the directional gyro 51 to provide anair passage 58 between the two instrument housings.

From the foregoing, it will be apparent that by practicing the teachingsof the present invention it is possible to provide a synthetic horizoninstrument wherein the horizon is simulated in a much more realistic andnatural manner than with any previously known instrument. It followsthat when flying with the benet of the improved artificial horizon apilot will respond to it in a much more natural and effortless mannerthan with prior devices, with the result that instrument flight may beaccomplished much more safely and with greater ease than heretofore.

While only two modiiications of the structure of the device have beenshown, it should be realized that it is subject to numerous othermodifications and variations Within the scope of the appended claims.

The invention described herein, if patented, may be manufactured andused by or for the Government for governmental purposes without thepayment to me of any royalty thereon.

Having thus described the invention, what is claimed as new is:

1. In an aircraft instrument, the combination of a dial; a horizonindicator consisting of a long narrow bar extending substantially acrossthe dial; means for maintaining the horizon indicator in level,horizontal position; said means including an attitude gyroscope and amechanical linkage between the gyroscope and horizon bar; together withmeans responsive to turning movements of the aircraft for effectingapparent longitudinal movement of the horizon indicator; said last namedmeans including a light source, a lens associated with said light sourceto focus its rays into a wide illuminated field of generally parallelrays; an optical screen includling alternate transparent and opaqueportions, and a turn indicating gyroscope responsive to turningmovements of the aircraft for moving the screen to cause lateralmovement of the illuminated field; the turn indii eating gyroscope beingseparate from and indef pendent of the attitude gyroscope.

2. In an aircraft instrument, the combination of a horizon indicator ofgenerally linear form; means for maintaining the horizon indicator inlevel, horizontal position, said means including a gyroscope; and turnindicating means for effecting apparent longitudinal movement of thehorizon indicator; said turn indicating means including a light source,a slotted rotary optical screen to pass interrupted light rays from saidsource to the horizon indicator and a turn indicating gyroscoperesponsive to turning movements of the aircraft for rotating the screen.

3. In an aircraft instrument, the combination of an artificial horizon;optical instrumentalities comprising a light source and a slotted screenfor causing light bands to move along said artificial horizon, and meansresponsive to turning movements of the aircraft to control the speed anddirection of movement of said light bands.

4. In an aircraft instrument, the combination of a mechanicallycontrolled artificial horizon consisting of a long narrow bar; opticalinstrumentalities comprising a light source and a ro tary screen forcausing light bands to move along said bar, and mechanicalinstrumentalities responsive to turning movements of the aircraft tocontrol the speed and direction of movement of said light bands.

5. In an aircraft instrument, the combination of a dial, an artiicialhorizon having at least one reilecting surface, a light source, meansfor projecting light rays from the source to said horizon from whencethey are reflected to the dial, gyro means responsive to movement of theaircraft about its longitudinal axis for effecting a correspondingrotary movement of said horizon with respect to the dial, said gyromeans being responsive to movement of the aircraft about its horizontaltransverse axis to effect a vertical movement of the horizon withrespect to the dial, means for interrupting the light rays, to produce aseries of light and dark areas on the dial along side of said horizon,and a gyroscope for actuating said interrupting means to simulate amoving landscape when the aircraft turns, all three conditions of theactual horizon being thus indicated upon the dial.

6. In an aircraft instrument, in combination, a pair of gyroscopes, anarticial horizon conu nected to one of the gyroscopes, a light sourcemounted between the gyroscopes, means for projecting the light rays fromthe source to the artificial horizon, and means actuated by the othergyroscope for interrupting the light rays at spaced intervals to producea series of light and dark areas upon the horizon.

LUIS DE FLOREZ.

REFERENCES CITED The following references are of record in. the

Y ille of this patent:

UNITED STATES PATENTSl

